1. Field of the Invention
The present invention generally relates to a self-routing switching system, and particularly to a self-routing switching system which is optimal for use for high-speed packet switching or asynchronous transfer mode (ATM) switching.
2. Description of the Related Art
As is well known, a self-routing switch module network providing speech paths is suitable for cases of high-speed switching to different outgoing lines for each packet or each cell (asynchronous transfer mode blocks), such as high-speed packet switching or asynchronous transfer mode switching, and for cases where centralized control of the speech path by software is not desired because of the need for high speed call processing.
Conventional self-routing systems have been proposed in, for example: The 6th Annual Symposium on Computer Architecture, 23-25 Apr. 1979, IEEE, (New York, US), T.-Y. Feng et al.: "A microprocessor controlled asynchronous circuit switching network", pages 202-215; IEEE Journal on Selected Areas in Communications, volume SAC-4, No. 8, Nov. 1986, IEEE (New York, US), J. S. Turner: "Design of an integrated services Packet network", pages 1373-1380; International Journal of Electronics, volume 56, No. 6, June 1984, (Basingstoke, Hampshire, GB), S. K. Paranjpe et al.: "A new concept for supermodular alignment network", pages 815-822; IEEE Transactions on Computer, volume C-34, No. 2, Feb. 1985, IEEE, (New York, US), M. Kumar et al.: "Switching strategies in shuffle-exchange Packet-switched networks", pages 180-186; Journal of the Institution of Electronic and Radio Engineers, volume 56, No. 6/7, June/July 1986, IEEE, (London, GB), M. Nagasawa et al.: "Packet switching network access protocols for multi-media packet communications", pages 243-247: European Patent Application No. 0113639 (SERVEL et al.) 18 July 1984; Proceedings of the 1981 International Conference on Parallel Processing, 25-28 Aug. 1981, IEEE, (New York, US), R. J. McMillen et al.: "Performance and implementation of 4.times.4 switching nodes in an interconnection network for PASM", pages 229-233; Belgium Application No. 904100 (ITT) 24 July 1986; European Patent Application No. 0206403 (RACAL) 30 Dec. 1986; and United States patent application Ser. Nos. 157,621, filed Feb. 19, 1988, 198,089, filed May 24, 1988, 280,723 filed Oct. 6, 1988 and 320,574 filed Mar. 9, 1989, now U.S. Pat. Nos. 4,920,531 issued Apr. 24, 1990, 4,837,761 issued June 6, 1989, 4,993,018 issued Feb. 12, 1991 and 4,965,790 issued Oct. 23, 1990, respectively. filed Oct. 6, 1988.
However, none of the above-identified references disclose a self-routing switching system in which a self-routing switch module network is doubled.